kottke in XHTML/CSS
Here's a quick version (took me 45 minutes) of kottke.org done in valid XHTML and CSS. It's not ideal, as there's some weird spacing thing at the top of the page in Mozilla and the whole layout is fixed instead of liquid. But that's Jason's prerogative; I just wanted to show that it could be done.
I took some liberties with leaving out most of the content, just out of laziness. But there you go.